Subsea test trees are used in a variety of subsea well applications. A subsea test tree enables well testing and well clean-up operations to be conducted from an offshore floating rig. The subsea test tree provides a fast acting mechanism to shut-in a well with two barriers while preventing discharge of landing string contents into a riser. The subsea test tree also enables disconnection of the landing string from the test string. In many applications, ball valves are used in the subsea test tree as a primary barrier along an internal access passage of the subsea test tree.